Display device and process for production thereof

Abstract

A display device includes a first substrate and a second substrate disposed opposite to each other, and a display medium including an insulating liquid and electrophoretic colored particles dispersed therein and disposed between the first and second substrates. A first electrode and a second electrode are provided for applying a voltage to the display medium so as to move the colored particles between the first and second electrodes to effect a display depending on a voltage applied to the first and second electrodes. The electrophoretic colored particles are distributed uniformly without localization by incorporating the display medium in a plurality of light-transmissive tubes, and disposing and fixing the plurality of tubes in intimate contact with each other between the first and second substrates.

1. A display device, comprising:
 a first substrate and a second substrate disposed opposite to each other;  
 a display medium comprising an insulating liquid and electrophoretic colored particles dispersed therein and disposed between the first and second substrates; and  
 first electrodes and second electrodes for applying a voltage to the display medium so as to move the colored particles between a pair of a first electrode and a second electrode to effect a display depending on a voltage between the pair of first and second electrodes, wherein  
 a plurality of light-transmissive tubes are each filled with the display medium and are disposed parallel to each other between the first and second substrates,  
 a plurality of the first electrodes in the form of stripes are disposed between the first substrate and the tubes so that each first electrode extends in alignment with an associated one tube, and  
 the second electrodes are disposed to intersect the first electrodes.  
 
   
   
     2. A display device according to  claim 1 , wherein the second electrodes are disposed between the tubes and the second substrate, and the colored particles are moved vertically to the substrates. 
   
   
     3. A display device according to  claim 2 , wherein a pair of the first electrodes and the first substrates, or a pair of the second electrodes and the first substrate, or a pair of the second electrodes and the second substrate, is light-transmissive. 
   
   
     4. A display device according to  claim 2 , wherein an electroconductive film is disposed between the second electrodes and the tubes. 
   
   
     5. A display device according to  claim 1 , wherein the first electrodes and the second electrodes are both disposed between the first substrate and the tubes while being electrically insulated from each other, and the colored particles are moved parallel to the substrates. 
   
   
     6. A display device according to  claim 4 , wherein either the second substrate is light-transmissive, or the first and second electrodes and the second substrate are light-transmissive. 
   
   
     7. A display device according to  claim 1 , wherein the light-transmissive tubes are formed of a resin. 
   
   
     8. A display device according to  claim 1 , wherein the light-transmissive tubes are flexible. 
   
   
     9. A display device according to  claim 1 , wherein the insulating liquid and the colored particles are colored in different colors. 
   
   
     10. A display device according to  claim 1 , wherein one of the insulating liquid and the colored particles is colored in yellow, magenta or cyan, and is separately contained in different tubes for respective colors. 
   
   
     11. A display device according to  claim 10 , wherein the tubes of yellow, magenta and cyan are arranged in a prescribed order. 
   
   
     12. A display device according to  claim 1 , wherein the second electrodes are formed in stripes and disposed to intersect the first electrodes at right angles to form an electrode matrix. 
   
   
     13. A process for producing a display device according to  claim 1 , comprising:
 forming a stripe first electrode on an outer surface of and in a longitudinal direction of a light-transmissive tube comprising an insulating material,  
 filling a tube with a display medium comprising an insulating liquid and electrophoretic colored particles dispersed therein, and  
 disposing and fixing a plurality of tubes between a first substrate and a second substrate, one of which has been provided with second electrodes, so that the first electrode on the tube contacts the first substrate.  
 
   
   
     14. A process according to  claim 13 , wherein the insulating liquid and the colored particles are simultaneously introduced in the tube. 
   
   
     15. A process according to  claim 13 , wherein the insulating liquid and the colored particles are separately introduced into the tube. 
   
   
     16. A process according to  claim 13 , wherein the light-transmissive tube has a rectangular cross section. 
   
   
     17. A process according to  claim 13 , wherein the light-transmissive tubes are flexible and are deformed while changing their sectional shape to be in intimate contact with each other when the tubes are disposed and fixed between the first and second substrates. 
   
   
     18. A display device, comprising:
 a first substrate and a second substrate disposed opposite to each other;  
 a display medium comprising an insulating liquid and electrophoretic colored particles dispersed therein and disposed between the first and second substrates; and  
 first electrodes and second electrodes for applying a voltage to the display medium so as to move the colored particles between a pair of a first electrode and a second electrode to effect a display depending on a voltage between the pair of first and second electrodes, wherein  
 a plurality of light-transmissive tubes are each filled with the display medium and are disposed parallel to each other between the first and second substrates,  
 each tube is provided with inner wall projections disposed at a regular interval in its longitudinal direction,  
 a plurality of the first electrodes in the form of stripes are disposed between the first substrate and the tubes so that each first electrode extends in alignment with an associated one tube, and  
 the second electrodes are disposed to intersect the first electrodes.  
 
   
   
     19. A display device according to  claim 18 , wherein the second electrodes are disposed between the tubes and the second substrate, and the colored particles are moved vertically to the substrates within a section partitioned by neighboring two of the inner wall projections. 
   
   
     20. A display device according to  claim 19 , wherein a pair of the first electrodes and the first substrate, or a pair of the second electrodes and the second substrate, is light-transmissive. 
   
   
     21. A display device according to  claim 19 , wherein an electroconductive film is disposed between the second electrodes and the tubes. 
   
   
     22. A display device according to  claim 18 , wherein the first electrodes and the second electrodes are both disposed between the first substrate and the tubes while being electrically insulated from each other, and the colored particles are moved parallel to the substrates within a section partitioned by neighboring two of the inner wall projections. 
   
   
     23. A display device according to  claim 22 , wherein either the second substrate is light-transmissive, or the first and second electrodes and the second substrate are light-transmissive. 
   
   
     24. A display device according to  claim 18 , wherein each tube is provided with the inner wall projections along its side wall perpendicular to the substrates. 
   
   
     25. A display device according to  claim 18 , wherein the light-transmissive tubes are formed of a resin. 
   
   
     26. A display device according to  claim 18 , wherein the light-transmissive tubes are flexible. 
   
   
     27. A display device according to  claim 18 , wherein the insulating liquid and the colored particles are colored in different colors. 
   
   
     28. A display device according to  claim 18 , wherein one of the insulating liquid and the colored particles is colored in yellow, magenta or cyan, and is separately contained in different tubes for respective colors. 
   
   
     29. A display device according to  claim 28 , wherein the tubes of yellow, magenta and cyan are arranged in a prescribed order. 
   
   
     30. A display device according to  claim 18 , wherein the second electrodes are formed in stripes and disposed to intersect the first electrodes at right angles to form an electrode matrix. 
   
   
     31. A process for producing a display device according to  claim 18 , comprising:
 forming a stripe first electrode on an outer surface of and in a longitudinal direction of a light-transmissive tube comprising an insulating material,  
 forming projections at a regular interval in a longitudinal direction on an inner wall of the tube,  
 filling a tube with a display medium comprising an insulating liquid and electrophoretic colored particles dispersed therein, and  
 disposing and fixing a plurality of tubes between a first substrate and a second substrate, one of which has been provided with second electrodes, so that the first electrode on the tube contacts the first substrate.  
 
   
   
     32. A process according to  claim 31 , wherein the insulating liquid and the colored particles are simultaneously introduced in the tube. 
   
   
     33. A process according to  claim 31 , wherein the insulating liquid and the colored particles are separately introduced into the tube. 
   
   
     34. A process according to  claim 31 , wherein the light-transmissive tube has a rectangular cross section. 
   
   
     35. A process according to  claim 31 , wherein the light-transmissive tubes are flexible and are deformed while charging their sectional shape to be in intimate contact with each other when the tubes are disposed and fixed between the first and second substrates. 
   
   
     36. A process according to  claim 31 , wherein the light-transmissive tube comprises a heat-shrinkable material, and the inner wall is formed by heat-shrinkage of the tube. 
   
   
     37. A process according to  claim 31 , wherein the inner wall projections are formed by pressing the light-transmissive tube with a pressing tool. 
   
   
     38. A process according to  claim 31 , wherein the light-transmissive tubes are each provided with external projections on each outer wall, and the external projections are pressed inside to form the inner wall projections when the light-transmissive tubes are disposed and fixed between the first and second substrates.